Kitty/ˈkɪti/ Definition 1 of 2Pro Tip 1/3Affectionate Term Often used to show affection towards cute, small cats by their owners or cat lovers. Look at that adorable kitty playing with the yarn! Pro Tip 2/3Childish Connotation May sound childish or less formal when referring to a cat, especially in serious contexts. My little sister always asks to pet the neighbor's kitty. Pro Tip 3/3Kitty vs Cat Kitty implies the cat is young or small compared to adult cats, which are just called cats. Our kitty will grow into a big, strong cat one day.